WO2023057540A1

WO2023057540A1 - Process for preparing enzymatically-treated food compositions with gos and low lactose content and food compositions thereof

Info

Publication number: WO2023057540A1
Application number: PCT/EP2022/077764
Authority: WO
Inventors: Sabine SRES; Youyun LIANG; Vishist Kumar JAIN; Clélia VERNALDE; Martin Stucki
Original assignee: Société des Produits Nestlé S.A.
Priority date: 2021-10-07
Filing date: 2022-10-06
Publication date: 2023-04-13
Also published as: AR127313A1

Abstract

The invention relates to a process for preparing an enzymatically-treated food composition. A milk substrate is provided and is contacted with a beta-galactosidase having transgalactosylation activity. In particular, the beta-galactosidase having transgalactosylation activity is allowed to react for 10-360 minutes at 30-65°C and then inactivated. The milk substrate is then contacted with a lactase which is devoid of transgalactosylation activity. The lactase devoid of transgalactosylation activity is allowed to react for 10-180 minutes at 30-55°C and then inactivated. The invention also relates to an alternative process comprising a step where the beta-galactosidase and the lactase devoid of transgalactosylation activity are allowed to react simultaneously. The invention also relates to another alternative process comprising a step where the beta-galactosidase is allowed to react alone and a subsequent step where the beta-galactosidase and the lactase devoid of transgalactosylation activity are allowed to react simultaneously. The invention furthermore relates to an enzymatically-treated food composition obtained by such different processes, a food product comprising such food composition and a process for preparing such a food product.

Description

PROCESS FOR PREPARING ENZYMATICALLY-TREATED FOOD COMPOSITIONS WITH GOS AND LOW LACTOSE CONTENT AND FOOD COMPOSITIONS THEREOF

TECHNICAL FIELD

The present invention relates generally to processes for preparing food compositions comprising a substantial content of galactooligosaccharides (GOS) and with low content of lactose, preferably free from lactose. It also relates to food compositions comprising galactooligosaccharides and with low content of lactose, preferably free from lactose. It further relates to food products comprising such food compositions and way of producing such food products.

BACKGROUND OF THE INVENTION

Food products prepared with dairy ingredients are appreciated by consumers and are widely consumed all over the world. With the increased prevalence of metabolic diseases, health-conscious consumers are looking for and are switching towards food products prepared with dairy ingredients with a good and balanced nutritional profile.

In particular, food products prepared with dairy ingredients comprise, inter alia, sugars, including inherent lactose, that contribute to achieve the desired taste and texture.

However, sugars, including inherent lactose, are known to be calorific. For health reasons, there is a desire to reduce the amount of sugars, including lactose and to replace with healthier ingredients, e.g. fibers.

In addition, fibers are key macronutrients. In particular, the intake of a substantial amount of fibers supports a healthy and balanced diet. However, some food products prepared with dairy ingredients comprise a minimal amount of fibers.

Furthermore, a significant part of adult world population (around 70%) suffers from lactose intolerance which results from a natural decline of lactase level in the human adult which is called lactase deficiency (LD) or lactase non-persistence (LNP). Due to absence of or low lactase activity in such individuals, undigested lactose reaches the colon where it is degraded to lactic acid, acetic acid and carbon dioxide by intestinal bacteria, inducing the symptoms of lactose intolerance. This leads to unpleasant and social-disabling adverse reactions such as abdominal pain, bloating, flatulence, and diarrhoea. Hence, there is a need to provide food products having low level or which are free from lactose. But this should be achieved without sacrificing taste and texture, as lactose is a key carbohydrate of dairy compositions/products contributing to achieve a pleasant taste and texture.

For the reasons given above, there is a desire to improve the nutritional profile of food products prepared with dairy ingredients by reducing the amount of lactose, to achieve low- lactose, preferably lactose-free food compositions while substantially increasing the amount of fibers. In particular, there is a need to achieve the foregoing while maintaining an acceptable organoleptic profile for the food composition.

Any reference to prior art documents in this specification is not to be considered an admission that such prior art is widely known or forms part of the common general knowledge in the field.

SUMMARY OF THE INVENTION

The object of the present invention is to improve the state of the art, and in particular to provide a process that overcomes the problems of the prior art and addresses the needs described above, or at least to provide a useful alternative.

It has been surprisingly found that the object of the present invention could be achieved by the subject matter of the independent claims. The dependent claims further develop the idea of the present invention.

A first aspect of the invention proposes a process for preparing an enzymatically- treated food composition comprising the steps of:

(a) providing a milk substrate, comprising a total solids content of 10wt.% to 60wt.%,

(b) contacting the milk substrate with a first enzyme, the first enzyme consisting of a betagalactosidase having transgalactosylation activity,

(c) allowing the first enzyme to react for 10-360 minutes at 30-65°C to obtain a first enzymatically-treated milk substrate,

(d) fully or partially inactivating the first enzyme in the first enzymatically-treated milk substrate to obtain a first partially or fully enzyme-inactivated milk substrate,

(e) contacting the first partially or fully enzyme-inactivated milk substrate with a second enzyme, the second enzyme consisting of a lactase which is devoid of transgalactosylation activity,

(f) allowing the second enzyme to react for 10-180 minutes at 30-55°C to obtain a second enzymatically-treated milk substrate. (g) fully or partially inactivating the second enzyme in the second enzymatically-treated milk substrate.

A second aspect of the invention proposes a process for preparing an enzymatically- treated food composition comprising the steps of:

(a') providing a milk substrate, comprising a total solids content of 10wt.% to 60wt.%,

(b') contacting the milk substrate with a first enzyme consisting of a beta-galactosidase having transgalactosylation activity and a second enzyme consisting of a lactase which is devoid of transgalactosylation activity,

(c') allowing the first and the second enzyme to react simultaneously for 25-180 minutes at 30 to 55°C to obtain an enzymatically-treated milk substrate,

(d') fully or partially inactivating the first and second enzymes in the enzymatically-treated milk substrate.

A third aspect of the invention proposes a process for preparing an enzymatically- treated food composition comprising the steps of:

(a") providing a milk substrate, comprising a total solids content of 10wt.% to 60wt.%, (b") contacting the milk substrate with a first enzyme consisting of a beta-galactosidase having transgalactosylation activity,

(c") allowing the first enzyme to react for 10-360 minutes at 30-65°C to obtain a partially enzymatically-treated milk substrate,

(d") contacting the partially enzymatically-treated milk substrate with a second enzyme consisting of a lactase which is devoid of transgalactosylation activity,

(e") allowing the first enzyme and the second enzyme to react simultaneously for 10-180 minutes at 30 to 55°C to obtain a fully enzymatically-treated milk substrate,

(f") fully or partially inactivating the first and second enzymes in the fully enzymatically- treated milk substrate.

The processes of first, second and third aspects of the invention enable to provide a food composition having an improved nutritional profile thanks to the combination of two enzymes: beta-galactosidase having transgalactosylation activity and lactase. In particular, the processes, including their conditions, enable the effective production of GOS and the effective hydrolysis of lactose while limiting undesirable reverse reactions such as GOS hydrolysis. The processes result in food compositions having a substantial amount of fibers, in particular GOS, and having reduced total sugars content, including lactose. In particular, the food compositions comprise a minimal amount of lactose, preferably no lactose, such that the food compositions are adapted for consumers who limit consumption of lactose, including consumers suffering from lactose intolerance. Despite the change in sugar and fiber composition of such food compositions due to enzymatic treatments, the resulting food compositions maintain an acceptable organoleptic profile (taste and texture).

A fourth aspect of the invention proposes an enzymatically-treated food composition comprising 10-40 % by dry weight of milk protein; and 25-55% by dry weight of a mixture of lactose, glucose, galactose and galactooligosaccharide, said mixture containing: 0-4 % by weight of lactose, 8-45% by weight of glucose, 0.1-25% by weight of galactose and 35-90% by weight of galactooligosaccharide.

A fifth aspect of the invention proposes a food product comprising an enzymatically- treated food composition according to the fourth aspect of the invention.

A sixth aspect of the invention proposes a process for preparing a food product which comprises: the steps of preparing an enzymatically-treated food composition according to the first second or third aspect of the invention, or, the step of providing an enzymatically-treated food composition according to the fourth aspect of the invention.

These and other aspects, features and advantages of the invention will become more apparent to those skilled in the art from the detailed description of embodiments of the invention, in connection with the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the amount of lactose (triangles) and the amount of GOS (dots) over time when applying the process according to the first aspect of the invention on a milk substrate (cf. example 2).

Figure 2 shows the amount of lactose (triangles) and the amount of GOS (dots) over time when applying the process according to the third aspect of the invention on a milk substrate (cf. example 3).

Figure 3 shows the amount of lactose (triangles) and the amount of GOS (dots) over time when applying the process according to the second aspect of the invention on a milk substrate (cf. example 4).

DETAILED DESCRIPTION OF THE INVENTION

In the present context, the words "comprise", "comprising" and the like are to be construed in an inclusive sense, that is to say, in the sense of "including, but not limited to", as opposed to an exclusive or exhaustive sense.

In the present context, all numerical ranges should be understood to include each whole integer within the range.

In the present context, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

Unless noted otherwise, all percentages in the specification refer to weight percent, where applicable.

Unless defined otherwise, all technical and scientific terms have and should be given the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

In the present context, the term "beta-galactosidase having transgalactosylation activity" refers to one or more enzymes with enzymatic activity of enzyme class EC 3.2.1.23, also called beta-D-galactoside galactohydrolase, exo-(l->4)-beta-D-galactanase or lactase, which catalyses the hydrolysis of terminal non-reducing beta-D-ga lactose residues in beta-D- galactosides, as well as transgalactosylation by transferring a galactose moiety of a beta-D- galactoside to another sugar molecule.

In the present context, EC (Enzyme Committee) numbers refer to the definition of enzymatic activity and nomenclature given by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology as in force on 3rd July 2019.

In the present context, the terms "galacto-oligosaccharides" or "GOS" refer to oligosaccharides composed of different galactosyl residues (usually from 2 to 9 units) and a terminal glucose linked by (3-glycosidic bonds, such as (3-(l— 2), (3-(l— 3), (3-(l— 4), and (3-(l— 6). GOS are normally produced through the enzymatic conversion of lactose, especially an enzymatic conversion with at least one beta-galactosidase having transgalactosylation activity.

In the present context, the term "simple sugars" refers to mono- and di-saccharides. For example, this includes lactose, glucose and galactose.

In the present context, the term "inherent simple sugars" refers to mono- and disaccharides (e.g. lactose, glucose, galactose) which are inherently present in the ingredients of a food composition or a food product.

In the present context, the term "total sugar(s)" refers to all inherent simple sugars (e.g. lactose, glucose, fructose, galactose...) and all added (i.e. non-inherent) simple sugars (e.g. added sucrose) comprised a food composition or a food product. Hence, the term "total sugar content" refers to the content of all inherent simple sugars plus the content of all added simple sugars.

In the present context, the term "flavouring ingredients" refers to ingredients which are added to impart a flavour in the food composition or food product, e.g. chocolate flavour.

In the present context, the term "texturizing ingredients" refers to ingredients which are added to increase the texture, in particular the viscosity, of the food composition or food product.

In a first aspect, the invention relates to a process for preparing an enzymatically- treated food composition.

This process comprises a step (a) of providing a milk substrate, comprising a total solids content of 10wt.% to 60wt.%.

In a particular embodiment, the milk substrate may be a milk, i.e. non-human mammal milk, preferably cow milk. For example, the milk substrate may be skimmed milk, semiskimmed milk and/or whole milk.

In another embodiment, the milk substrate may be obtained from milk which has been modified in composition by adjustment of fat content, protein content, lactose content and/or water content. Adjustment of fat content and/or water may have been done by any method known in the art, e.g., by centrifugation, evaporation, condensation, ultrafiltration, nanofiltration, freeze-drying, spray-drying, reconstitution by addition of water, etc. Example methods are given, for example in 'The Technology of Dairy Products', edited by Ralph Early. For example, the milk substrate may be a concentrated milk, such as condensed milk.

In one preferred embodiment, the milk substrate may correspond to an aqueous composition comprising one or more dairy ingredients. The term "dairy ingredients" relates to ingredients derived from a non-human mammal milk, such as cow milk, goat milk, ewe milk, camel milk, donkey milk. For avoidance of doubt, the term "dairy ingredients" includes milk, i.e. non-human mammal milk, preferably cow milk. Preferably, the dairy ingredients are ingredients derived from cow milk. Examples of dairy ingredients include milk, milk fat, milk powder, skim milk, milk proteins, dairy curd, cream, buttermilk, condensed milk and combinations thereof. The milk may be a whole milk, semi-skimmed milk or a skimmed milk. The dairy curd corresponds to the dairy coagulum, optionally strained, which is obtained by treating dairy ingredients such as milk with rennet and/or lactic acid bacteria strains. Examples of milk proteins include casein, caseinate, casein hydrolysate, whey, whey hydrolysate, whey concentrate, whey isolate, milk protein concentrate, milk protein isolate, and combinations thereof. Furthermore, the milk proteins may include, for example, sweet whey, acid whey, a- lactalbumin, 0-lactoglobulin, bovine serum albumin, acid casein, caseinates, a-casein, 0- casein, and/or y-casein.

In a particular embodiment, the milk substrate corresponds to an aqueous composition obtained by reconstituting milk powder, lactose, whey permeate and/or sweet whey into an aqueous liquid, such as water and/or cow milk. By "milk powder", it is understood non-human mammal milk powder, preferably cow milk powder. For example, the milk substrate may be skimmed milk powder, semi-skimmed milk powder and/or whole milk powder reconstituted into water. More preferably, the milk substrate is sweet whey that has been reconstituted into water and/or cow milk. The cow milk may be skimmed milk, whole milk, semi-skimmed milk or combination thereof.

In another embodiment, the milk substrate corresponds to an aqueous composition obtained by reconstituting a milk protein concentrate and/or a whey protein concentrate into an aqueous liquid, such as water and/or cow milk. The term "milk protein concentrate" refers to a protein concentrate isolated from milk, for example by filtration technologies, and comprising from 40wt% to 80wt% milk proteins. The term "whey protein concentrate" refers to a protein concentrate isolated from milk whey, for example by filtration technologies, and comprising from 30wt% to 80wt% protein.

In a preferred embodiment, the milk substrate comprises a total solids content of 10wt.% to 55wt.%. Preferably, the milk substrate comprises a total solids content of 10wt.% to 50wt.%. More preferably, the milk substrate comprises a total solids content of 15wt.% to 35wt.%.

In another preferred embodiment, the milk substrate comprises at least 4 wt.% lactose by dry weight of the milk substrate. Preferably, the milk substrate comprises at least 8wt.%, at least 10wt% or at least 15wt% lactose by dry weight of the milk substrate. More preferably, the milk substrate comprises at least 20wt.%, preferably at least 25wt.% or at least 30wt.% lactose by dry weight of the milk substrate.

In a more preferred embodiment, the milk substrate comprises 4-60wt.% lactose by dry weight of the milk substrate, preferably 15-60wt.% or 15-45wt.% lactose by dry weight of the milk substrate, more preferably 20-45wt.% lactose by dry weight of the milk substrate.

These levels of total solids and/or lactose facilitate the hydrolysis of lactose and the formation of GOS during the enzymatic treatment with the first enzyme.

In a specific embodiment, the milk substrate may comprise from 0.3-30wt%, preferably 0.3-15wt%, more preferably 0.3-5% fat. In particular, the fat consists of milk fat and/or fat derived from vegetable oil. Vegetable oil may be any suitable vegetable oil, preferably palm oil. Milk fat may be derived from any suitable milk source, such as liquid milk or cream, milk powder or cream powder, butter, butter oil and/or anhydrous milk fat. Examples of liquid milk include semi-skimmed milk, cream, whole milk and mixtures thereof. Examples of milk powder include semi-skimmed milk powder, whole milk powder, and mixtures thereof.

In another embodiment, the milk substrate may further comprise 5-25% by weight of vegetable fat, e.g. palm oil.

The milk substrate may be combined with additional ingredients before step (b). In particular, the milk substrate may be combined with ingredients selected from the list consisting of vitamins, minerals, salts, bulking agents, flavouring ingredients, solid fat, vegetable oil, emulsifiers and combinations thereof.

The process of the first aspect further comprises a step (b) of contacting the milk substrate with a first enzyme. The first enzyme consists of a beta-galactosidase having transgalactosylation activity. Examples of beta-galactosidase having transgalactosylation activity include Nurica™ commercialized by Dupont™ Nutrition & Biosciences (newly IFF) and Zymstar™ commercialized by Dupont™ Nutrition & Biosciences (newly IFF). In an embodiment, the beta-galactosidase having transgalactosylation activity may be from Bacillus subtilis.

The process of the first aspect further comprises a step (c) of allowing the first enzyme to react for 10-360 minutes at 30-65°C, preferably at 35-60°C to obtain a first enzymatically- treated milk substrate. More preferably, the temperature of the enzymatic treatment with the first enzyme is of 35-55°C. Most preferably, the temperature of the enzymatic treatment with the first enzyme is of 38-50°C.

In a preferred embodiment, the first enzyme is allowed to react for 50-360 minutes or 100-360 minutes. More preferably, the first enzyme is allowed to react for 120-300 minutes. The enzymatic treatment with the first enzyme is performed at a temperature of 30-65°C, preferably of 35-60°C. More preferably, the enzymatic treatment with the first enzyme is performed at a temperature of 35-55°C. Most preferably, the enzymatic treatment with the first enzyme is performed at a temperature of 38-50°C

The enzymatic treatment with the first enzyme has the effect of reducing lactose of the milk substrate by partly converting the sugar into GOS. In particular, lactose of the milk substrate is hydrolysed by the beta-galactosidase into galactose and glucose. In addition, sugars, including lactose, are reduced by the beta-galactosidase at the expense of the formation of fibers, especially GOS. Hence, this enzymatic treatment results in the lowering of the amount of total sugars in the milk substrate while resulting in the increase of the amount of fibers, in particular GOS, in the milk substrate. Hence, this enzymatic treatment step is key to improve the nutritional profile of the milk substrate and therefore of the food composition prepared with the milk substrate. Indeed, the milk substrate and the resulting food composition have reduced total sugars content, including lactose and an improved amount of fibers, in particular GOS, which are not counted into the total sugar content.

The above-mentioned time/temperature conditions for the enzymatic reaction with the first enzyme are optimal conditions for the formation of GOS and reduction of lactose in a time-efficient manner. From industrial standpoint, it is key that the enzymatic treatment lasts a minimal time while producing significant amount of GOS. Especially, it has been observed that a significant amount of GOS can be produced in a minimal time, i.e. few minutes to few hours, at mild-high temperature, i.e. 30-65°C. In addition, the enzymatic treatment with the first enzyme should not be too long. Indeed, after a threshold amount of GOS is produced, beta-galactosidase tends to catalyse an undesirable reverse reaction, i.e. the hydrolysis of GOS. This reverse reaction results in the reduction of amount of GOS. Hence, the time/temperature conditions of the invention are such that the production of GOS is optimized while the phenomenon of GOS hydrolysis is limited.

The process of the first aspect of the invention also comprises a step (d) of fully or partially inactivating the first enzyme in the first enzymatically-treated milk substrate to obtain a first partially or fully enzyme-inactivated milk substrate. Preferably, the first enzyme in the first enzymatically-treated milk substrate is fully inactivated. The purpose of the inactivation step is to prevent undesirable substantial degradation of the GOS by further reaction of the beta-galactosidase.

The enzyme may be inactivated by any state of the art method, for example, by heat treatment, pH lowering (e.g. to below pH 4) or lowering water activity.

In a preferred embodiment, the inactivation step is performed by heat treating the first enzymatically-treated milk substrate at 70-150°C for 10-150 seconds, preferably at 72- 130°C for 10-120 seconds. The purpose of the heat treatment is to prevent substantial degradation of the GOS by further reaction of the beta-galactosidase, without creating excessive denaturation of protein of the milk composition or formation of Maillard reaction products.

The process of the first aspect of the invention further comprises a step (e) of contacting the first partially or fully enzyme-inactivated milk substrate with a second enzyme. The second enzyme consists of a lactase which is devoid of transgalactosylation activity. Examples of lactase which is devoid of transgalactosylation activity include GODO-YNL2 lactase commercialized by Dupont™ Nutrition Biosciences (newly IFF).

Lactases catalyse the hydrolysis of lactose into galactose and glucose. However, lactases possess the side activity of GOS hydrolysis and tend to degrade GOS. This side activity, which is even more pronounced when lactose concentration is low, is detrimental to the accumulation of GOS. Hence, it is key to limit the degradation of GOS by lactases in the process of the invention to maintain a substantial amount of GOS in the final food composition. It has been observed that lactases devoid of transgalactosylation activity have the least propensity to hydrolyze GOS compared to other lactases, thus allowing higher quantities of GOS to be accumulated. Hence, they are able to degrade GOS to a limited extent. In particular, in a preferred embodiment, the second enzyme hydrolyses less than 40%, preferably less than 30%, more preferably less than 25% of GOS until the second enzyme is inactivated. The process of the first aspect of the invention comprises a step (f) of allowing the second enzyme to react for 10-180 minutes at 30-55°C to obtain second enzymatically-treated milk substrate.

In a preferred embodiment, the second enzyme is allowed to react for 10-180 minutes preferably for 30-150 minutes, more preferably for 50-150 minutes to obtain second enzymatically-treated milk substrate. The temperature of the enzymatic treatment with the second enzyme is of 30-55°C, preferably 30-50°C, more preferably 35-45°C.

After the enzymatic treatment with the first enzyme, a significant part of the lactose, named residual lactose, is not degraded. The enzymatic treatment with the second enzyme enables to degrade the residual lactose to achieve a milk substrate and therefore a food composition with a minimal amount of lactose. This allows the preparation a food composition which has low level, preferably no lactose such that it can be consumed by people who limits consumption of lactose, including people suffering from lactose intolerance, with limited or no adverse reactions.

The above-mentioned time/temperature conditions enable to degrade the residual lactose in a time-efficient manner. For industrial standpoint, it is key that the enzymatic treatment with the second enzyme lasts a minimal time while degrading a sufficient amount of residual lactose. It is also key that the enzymatic reaction with the second enzyme lasts a minimal time to limit the degradation of GOS by the lactase. In particular, it has been observed that a significant amount of residual lactose can be degraded in a minimal time, i.e. few minutes to few hours, at mild temperature, i.e. 30-55°C. In addition, with such conditions, the hydrolysis of lactose is not only optimized but the degradation of GOS by lactases is also minimized.

The process comprises a step (g) of fully or partially inactivating the second enzyme in the second enzymatically-treated milk substrate. Preferably, the second enzyme in the second enzymatically-treated milk substrate is fully inactivated. The purpose of the inactivation step is to prevent undesirable further reaction of the lactase. For example, this avoids thorough degradation of GOS by further reaction of the lactase.

The enzyme may be inactivated by any state of the art method, for example, by heat treatment, pH lowering (e.g. to below pH 4) or lowering water activity. The inactivation may occur due to a step in the process for preparing the enzymatically-treated food product such as pasteurization, evaporation, spray drying. In a preferred embodiment, the inactivation step is performed by heat treating the second enzymatically-treated milk substrate for at 70-150°C for 10-150 seconds, preferably at 72-130°C for 10-120 seconds. If the enzymatically-treated food composition is not spray- dried, the inactivation step (g) is preferably performed by heat treating the second enzymatically-treated milk substrate at 140-145°C for 10-30 seconds. The purpose of the heat treatment is to prevent reaction of the lactase, as well as ensuring the microbiological stability of the enzymatically-treated milk composition, without creating excessive denaturation of protein or formation of Maillard reaction products. The combination of the two enzymatic treatments allows to provide a food composition having an improved nutritional profile. In particular, the food composition has a substantial amount of fibers, in particular GOS, and has reduced total sugars content. In addition, it comprises a minimal amount of lactose, preferably no lactose, such that the food composition is adapted for consumers who limit consumption of lactose, including consumers suffering from lactose intolerance. Despite the change of sugar & fiber composition after the two enzymatic treatments, the resulting food composition maintains an acceptable organoleptic profile (taste and texture).

It has been discovered that the yield of formation of GOS and of hydrolysis of lactose are improved when the two enzymatic reactions are sequential, i.e. when the second enzyme is added after the first enzyme has been inactivated.

In a further embodiment, the process does not comprise a step of addition of any ingredients comprising lactose during or after step (b). This ensures the content of lactose is minimal in the final food composition.

The enzymatically-treated food composition may be a powder or a liquid. For example, the enzymatically-treated food composition may be liquid milk, condensed milk (also known as evaporated milk) or milk powder. In a preferred embodiment, the enzymatically-treated food composition is a milk powder.

In an embodiment, the process further comprises a step of evaporating and/or spray drying the enzymatically-treated food composition after step (g). In a more preferred embodiment, the process further comprises a step of evaporating and spray drying the enzymatically-treated food composition after step (g), wherein the evaporation is prior the spray drying. These treatments, in particular spray drying, may be effective to fully inactivate any residual enzyme activities, if any, in the enzymatically-treated food composition. In a preferred embodiment, the enzymatically-treated food composition is a liquid and comprises at most lwt.% lactose or the enzymatically treated food composition is powderand it comprises an amount of lactose such that when the powder is reconstituted into a liquid, preferably water, the reconstituted powder comprises at most 1 g (i.e. 0-lg) of lactose per lOOmL. At these levels of lactose, the food composition is considered at least low in lactose and can be communicated as such according to food regulations, such as Brazilian regulations. In particular, these low amounts of lactose in the final food composition allow the consumption of the food composition by people who limit consumption of lactose, with limited or no adverse reactions/symptoms.

In a more preferred embodiment, the enzymatically-treated food composition is a liquid and comprises at most 0.1wt% (i.e. 0-0.1g) lactose or the enzymatically-treated food composition is a powder and comprises an amount of lactose such that when the powder is reconstituted into a liquid, preferably water, the reconstituted powder comprises at most 0.1g (i.e. 0-0. lg) of lactose per lOOmL. At these levels of lactose, the food composition is considered free from lactose and can be communicated as such according to regulations, such as Brazilian regulation. These very low amounts or absence of lactose in the final food composition allow the consumption of the food product by people who limit consumption of lactose, including consumers suffering from lactose intolerance, with limited or even no adverse reactions/symptoms.

In a more preferred embodiment, the enzymatically-treated food composition is a liquid and comprises at most 0.05wt%, at most 0.02wt.% or at most 0.01wt.% lactose or the enzymatically-treated food composition is a powder and comprises an amount of lactose such that when the powder is reconstituted into a liquid, preferably water, the reconstituted powder comprises at most 0.05g lactose, at most 0.02g lactose or at most 0.01g lactose per 100mL. Most preferably, the enzymatically-treated food composition is a powder and comprises no lactose when reconstituted in a liquid, preferably water, or the enzymatically- treated food composition is a liquid and comprises no lactose.

In a preferred embodiment, when the enzymatically-treated food composition is a powder, the above-mentioned level of lactose refers to levels obtained after reconstitution of 25g of the food composition in the form of powder in 180mL of a liquid. Preferably, the liquid is totally free from lactose, i.e. the liquid comprises 0% lactose. Example of such liquid include fruit juices, vegetable juices, water etc. Preferably, the liquid is water. Thanks to the enzymatic treatment, the enzymatically-treated food composition comprises a substantial amount of GOS, which are fibers. GOS supports health benefits into individuals, such as digestive health by acting as prebiotic. In addition, GOS contributes to fibers daily intake, fibers being key macronutrients for a healthy and balanced diet.

In particular, the enzymatically-treated food composition comprises at least lwt% galactooligosaccharide, preferably at least 4 wt.%, more preferably at least 8wt% galactooligosaccharide. In a more preferred embodiment, the enzymatically-treated food composition comprises l-35wt% GOS, preferably 4-35wt% GOS, more preferably 8-35wt.% GOS. Even more preferably, the enzymatically-treated food composition comprises 8-20wt% or 8-15wt% GOS.

Preferably, the enzymatically-treated food composition can be communicated as source of fibers according to food regulations, in particular Brazilian regulation. In particular, it comprises 2.5 g fibers per serving. For example, for a serving of 25g, it corresponds to 10g fibers per 100g of enzymatically-treated food composition. Preferably, the serving is of 25g.

In a most preferred embodiment, the enzymatically-treated food composition is a powder, in particular a milk powder.

More information relative to the enzymatically-treated food composition are provided below in the fourth aspect of the invention.

In a second aspect, the invention relates to an alternative process for preparing an enzymatically-treated food composition.

The process comprises a step (a') of providing a milk substrate, comprising a total solids content of 10wt.% to 60wt.%. The milk substrate is a milk substrate as described in the first aspect of the invention.

The process further comprises a step (b') of contacting the milk substrate with a first enzyme consisting of a beta-galactosidase having transgalactosylation activity and a second enzyme consisting of a lactase which is devoid of transgalactosylation activity. The first enzyme is a first enzyme as described in the first aspect of the invention. The second enzyme is a second enzyme as described in the first aspect of the invention. In particular, advantages of the first enzyme and the second enzyme are described in the first aspect of the invention.

The process comprises a step (c') of allowing the first and the second enzyme to react simultaneously for 25-180 minutes at 30-55°C, preferably of 35-50°C, more preferably at 35- 45°C to obtain an enzymatically-treated milk substrate. In a preferred embodiment, the first and the second enzymes are allowed to react simultaneously for 25-100 minutes. More preferably, the first and the second enzymes are allowed to react simultaneously for 25-80 minutes. Even more preferably, the first and the second enzymes are allowed to react simultaneously for 30-65 minutes. The first and the second enzymes are allowed to react simultaneously at a temperature of 30-55°C, preferably of 35-50°C, more preferably of 35-45°C.

It has been discovered that a substantial amount of GOS can be formed and a substantial amount of lactose can be hydrolysed when the two enzymatic treatments are performed simultaneously instead of being sequential. Despite a lower yield for GOS formation and lactose hydrolysis compared to sequential enzymatic treatments, the yield remains satisfactory when the enzymatic treatments are simultaneous. It is possible to achieve a food composition with an improved nutritional profile while maintaining an acceptable organoleptic profile when applying simultaneously both enzymatic treatments. In particular, the food composition has a significant amount of fibers, i.e. GOS and has reduced total sugars content. In addition, it comprises a minimal amount of lactose, preferably no lactose, such that the food product is adapted for consumers who limit consumption of lactose, including consumers suffering from lactose intolerance. A process with simultaneous enzymatic treatments may be advantageous from an industrial standpoint compared to a process with sequential enzymatic treatments. Indeed, it may be easier to implement at a factory scale, more cost-efficient and faster as it minimizes the number of steps and equipment needed. For example, only one inactivation step is needed.

An optimized yield for the formation of GOS and for the hydrolysis of lactose is obtained for the process of the second aspect of the invention with the above-mentioned time/temperature conditions. In the process according to the second aspect of the invention, the first and second enzymes act simultaneously. This means that the enzymes may not only compete for the same substrate but the product of one enzyme may be the substate of another enzyme. This leads to undesirable reactions. For example, the GOS formed by the first enzyme may be hydrolyzed by the second enzyme. Hence, it is key but intricate to implement conditions for achieving the highest yield possible. In particular, it has been discovered that the conditions described above ensure an optimized enzymatic formation of GOS and enzymatic hydrolysis of GOS while limiting the enzymatic hydrolysis of GOS by reverse reaction of beta-galactosidase or by action of lactase devoid of transgalactosylation activity. The process comprises a step (d') of fully or partially inactivating the first and second enzymes in the enzymatically-treated milk substrate. Preferably, the first and second enzymes in the enzymatically-treated milk are fully inactivated.

The enzyme may be inactivated by any state of the art method, for example, by heat treatment, pH lowering (e.g. to below pH 4) or lowering water. The inactivation may occur due to a step in the process for preparing the enzymatically-treated food composition such as pasteurization, evaporation, spray drying.

In a preferred embodiment, the inactivation step is performed by heat treating the enzymatically-treated milk substrate at 70-150°C for 10-150 seconds, preferably at 72-130°C for 10-120 seconds. If the enzymatically food-treated food composition is not spray-dried, the inactivation step (d') is preferably performed by heat treating the enzymatically-treated milk substrate at 140-145°C for 10-30 seconds. The purpose of the heat treatment is to prevent reaction of the lactase and beta-galactosidase, as well as ensuring the microbiological stability of the enzymatically-treated food composition, without creating excessive denaturation of protein or formation of Maillard reaction products.

In a further embodiment, the process does not comprise a step of addition of any ingredients comprising lactose during or after step (b'). This ensures the content of lactose is minimal in the final food composition.

In a preferred embodiment, the process further comprises a step of evaporating and/or spray drying the enzymatically-treated food composition after step (d'). In a more preferred embodiment, the process further comprises a step of evaporating and spray drying the enzymatically-treated food composition after step (d'), wherein the evaporation is prior the spray drying. These treatments, in particular spray drying, may be effective to fully inactivate any residual enzyme activities, if any, in the enzymatically-treated food composition.

The enzymatically-treated food composition is an enzymatically-treated food composition as described in the first aspect of the invention. In particular, the features of the enzymatically- treated food composition as described in the first aspect of the invention are applicable to the enzymatically-treated food composition of the present second aspect of the invention.

More information relative to the enzymatically-treated food composition are provided below in the fourth aspect of the invention. In a third aspect, the invention relates to another alternative process for preparing an enzymatically-treated food composition.

The process comprises a step (a") of providing a milk substrate, comprising a total solids content of 10wt.% to 60wt.%. The milk substrate is a milk substrate as described in the first aspect of the invention.

The process further comprises a step (b") of contacting the milk substrate with a first enzyme consisting of a beta-galactosidase having transgalactosylation activity. The first enzyme is a first enzyme as described in the first aspect of the invention. In particular, advantages of the first enzyme are described in the first aspect of the invention.

The process also comprises a step (c") of allowing the first enzyme to react for 10-360 minutes at 30-65°C, preferably 35-60°C, more preferably 35-55°C, most preferably 38-50°C to obtain a partially enzymatically-treated milk substrate.

In a preferred embodiment, the first enzyme is allowed to react for 100-360 minutes. More preferably, the first enzyme is allowed to react for 150-320 minutes. Most preferably, the first enzyme is allowed to react for 200-320. The first enzyme is allowed to react at a temperature of 30-65°C, preferably of 35-60°C, more preferably of 35-55°C, most preferably 38-50°C.

The advantages of this step are the same as the ones described for step (c) of the first aspect of the invention. In particular, the temperature and time conditions allow optimal formation of GOS and optimal reduction of lactose in a time-efficient manner.

The process comprises a step (d") of contacting the partially enzymatically-treated milk substrate with a second enzyme consisting of a lactase which is devoid of transgalactosylation activity. The second enzyme is a second enzyme as described in the first aspect of the invention. In particular, advantages of the second enzyme are described in the first aspect of the invention.

The process further comprises a step (e") of allowing the first enzyme and the second enzyme to react simultaneously for 10-180 minutes at 30 to 55°C, preferably 35°C to 50°C, more preferably at 35-45°C to obtain a fully enzymatically-treated milk substrate.

In a preferred embodiment, the first enzyme and the second enzyme are allowed to react simultaneously for 50-150 minutes. In a more preferred embodiment, the first enzyme and the second enzyme are allowed to react simultaneously for 50-120 minutes. The first enzyme and the second enzyme are allowed to react simultaneously at a temperature of 30 to 55°C, preferably 35°C to 50°C, more preferably at 35-45°C. In the process according to the third aspect, the first enzyme is allowed to react alone for a predetermined time before contacting the milk substrate with the second enzyme. This allows the formation of a substantial amount of GOS before contacting with the second enzyme. As the second enzyme tends to degrade GOS, it is only added at a late stage in the enzymatic reaction. This limits the degradation of GOS by the second enzyme while providing enough time to the second enzyme to degrade residual lactose to reach a minimal amount of lactose in the final food composition.

Similarly to the process of the second aspect, the yield of GOS formation and lactose hydrolysis is satisfactory, even it is lower than when the enzymatic treatments are sequential. In particular, it enables to achieve a food composition having the same benefit as in the second and in the first aspect of the invention, i.e. improved nutritional profile, acceptable organoleptic profile, significant amount of fibers (i.e. GOS), reduced total sugars cotent, and minimal amount or no lactose.

This process may be advantageous from an industrial standpoint compared to a process with sequential enzymatic treatment. Indeed, it may be easier to implement, more cost-efficient and faster as it minimizes the number of steps and equipment needed. For example, only one inactivation step is needed. Moreover, as the second enzymes is only added at the end, it limits undesirable reactions that occur when the two enzymatic treatments are simultaneous from the beginning to the end.

The process comprises a step (f") of fully or partially inactivating the first and second enzymes in the fully enzymatically-treated milk substrate. Preferably, the first and second enzymes in the fully enzymatically-treated milk are fully inactivated. The inactivation step is an inactivation step as described in the second aspect of the invention.

In a further embodiment, the process does not comprise a step of addition of any ingredients comprising lactose during or after step (b"). This ensures the content of lactose is minimal in the final food composition.

In a preferred embodiment, the process further comprises a step of evaporating and/or spray drying the enzymatically-treated food composition after step (f"). In a more preferred embodiment, the process further comprises a step of evaporating and spray drying the enzymatically-treated food composition after step (f"), wherein the evaporation is prior the spray drying. These treatments, in particular spray drying, may be effective to fully inactivate any residual enzyme activities, if any, in the enzymatically-treated food composition. The enzymatically-treated food composition is an enzymatically-treated food composition as described in the first aspect of the invention. In particular, the features of the enzymatically-treated food composition as described in the first aspect of the invention are applicable to the enzymatically-treated food composition of the present second aspect of the invention.

In a fourth aspect, the invention relates to an enzymatically-treated food composition.

The enzymatically-treated food composition comprises 10-40 %, preferably 10-30%, more preferably 10-20% by dry weight of milk protein.

The enzymatically-treated food composition also comprises 10-55%, preferably 10- 40%, more preferably 15-35% by dry weight of a mixture of lactose, glucose, galactose and galactooligosaccharide.

Said mixture of lactose, glucose, galactose and galactooligosaccharide contains 0-4 % by weight of lactose, 8-45% by weight of glucose, 0.1-25% by weight of galactose and 35-90% by weight of galactooligosaccharide.

In a preferred embodiment, the mixture of lactose, glucose, galactose and galactooligosaccharide contains 0-2%, more preferably 0-1.5%, most preferably 0-0.2% by weight of lactose. In another preferred embodiment, the mixture of lactose, glucose, galactose and galactooligosaccharide contains 20-45%, more preferably 30-45% by weight of glucose. In another preferred embodiment, the mixture of lactose, glucose, galactose and galactooligosaccharide contains 5-25%, more preferably 10-25% by weight of galactose. In another preferred embodiment, the mixture of lactose, glucose, galactose and galactooligosaccharide contains 35-75%, more preferably 35-60% by weight of galactooligosaccharide.

The weight ratio of galactose + GOS + glucose to lactose in the enzymatically-treated food composition is between 50 to 150, preferably between 50 to 100, more preferably between 50 to 80.

The enzymatically-treated food composition has a good nutritional profile. In particular, it comprises a substantial amount of fibres, in particular GOS which are beneficial for health and for balanced diets. In addition, it comprises reduced total sugars content, including a minimal amount of lactose. In particular, due to its low amount or absence of lactose, the food composition can be consumed by people who limits consumption of lactose, including consumers suffering from lactose intolerance with limited or no adverse reactions. The food composition has an acceptable organoleptic profile.

The features of the enzymatically-treated food composition described in the first, second and third aspects of the invention apply to the enzymatically-treated food composition according to the fourth aspect of the invention. Conversely, the features of the enzymatically- treated food composition described in the fourth aspect of the invention apply to the enzymatically-treated food composition described in the first, second and third aspects of the invention.

In a preferred embodiment, the enzymatically-treated food composition is obtainable according to the process of the first, the second or the third aspect of the invention.

A fifth aspect of the invention relates to a food product comprising an enzymatically- treated food composition according to the fourth aspect of the invention.

The enzymatically-treated food composition of the fourth aspect of the invention may be consumed as it is. But it may be further transformed into a food product or added to a food product to achieve a final food product with an improved nutritional profile, i.e. with a substantial amount of fibers, in particular GOS and reduced total sugars content. In particular, it may allow the preparation of food products which are low or free from lactose such that they can be consumed by people who limits consumption of lactose, including people suffering from lactose intolerance, with limited or no adverse reactions.

In a preferred embodiment, the food product is a food product selected from the list consisting of dairy products, confectionery products, beverage whiteners, beverage creamers, powdered cocoa beverages, powdered malt beverages, powdered or liquid coffee mix products, and/or nutritional or health-related food products. By "powdered or liquid coffee mix products", it is understood a powdered or liquid coffee mix products comprising a beverage creamer containing an enzymatically-treated food composition according to the invention in combination with soluble coffee.

Examples of dairy food products include UHT milk, chilled milk, milk powder, condensed milk, yogurt, fresh cheese, dairy desserts, fermented milk, kefir, dairy mousses, culinary creams, milkshakes, milk-containing smoothies.

Examples of confectionery products include chocolate, compound, pralines, water- or fat-based confectionery fillings, ganache, toffee ('caramel candy'), fudge, caramel analogues (e.g. Caramac®), chocolate truffles, Scottish tablet and hard candy (e.g. caramel hard candy and milk chews).

Examples of nutritional or health-related food products include food for special medical purposes (FSMP), nutritional supplement, ready to drink formula, infant formula, low-volume liquid supplement, meal replacement beverage.

In a most preferred embodiment, the food product is a dairy product, in particular a milk powder.

In a preferred embodiment, the food product does not comprise any additional components which comprise lactose other than the enzymatically-treated milk composition. In another preferred embodiment, the food product does not comprise any dairy ingredients in addition to the enzymatically-treated food composition.

In a particular embodiment, the food product comprises l-95wt.%, preferably 1- 90wt.% of the enzymatically-treated food composition.

The food product may comprise one or more additional components in addition to the enzymatically-treated food composition. Examples of additional ingredients include flavouring ingredients, emulsifiers, minerals, vitamins, texturizing ingredients, starter culture, probiotics, solid inclusions, plant proteins, preservatives, solid fat, vegetable oil, eggs, coffee, cocoa, chocolate, water, salts and combination thereof.

A sixth aspect of the invention relates to a process for preparing a food product.

The process comprises providing an enzymatically-treated food composition according to the fourth aspect of the invention.

Alternatively, the process comprises the steps of preparing an enzymatically-treated food composition according to the process of the first, second or third aspect of the invention.

In a further embodiment, the process further comprises a step of processing the enzymatically-treated food composition to obtain a food product. For example, the second enzymatically-treated food composition may be processed by pasteurization, sterilization, evaporation, homogenization, spray drying, freeze drying, fermentation, acidification, addition of at least one ingredient, smoothing, aeration, whipping, mixing, deaeration, tempering or combination thereof. The steps and order to be applied to the enzymatically- treated food composition to prepare a predetermined food product are well-known to a person skilled in the art. This process allows the preparation of a food product which has the advantages described in the fifth aspect of the invention.

The features of the food product described in the fifth aspect of the invention apply to the food product of the sixth aspect of the invention.

Those skilled in the art will understand that they can freely combine all features of the present invention disclosed herein. In particular, features described for the processes of the present invention may be combined with the products of the present invention and vice versa. Further, features described for different embodiments of the present invention may be combined.

Furthermore, where known equivalents exist to specific features, such equivalents are incorporated as if specifically referred in this specification. Further advantages and features of the present invention are apparent from the figures and non-limiting examples.

EXAMPLES

Example 1: Measurement of sugars & GOS.

GOS were measured by HPLC for examples 2-3. Especially, Oligosaccharides (OS) present in the samples are extracted in a water bath at 70°C. The extracted OS are fluorescently labeled by reaction (2h at 65°C) of 2-a nthranilic acid amide via formation of a Shift's base. The OS is treated with amyloglucosidase to avoid interferences of maltooligosaccharides and maltodextrin present in some finished products on the chromatogram. Labelled extracts are diluted with acetonitrile prior to injection on a HPLC- fluorimeter instrument equipped with a trapping column. Separation is performed on Amide- 80 3pm, 4.6x150 mm column, and labeled OS, including GOS, are detected on a fluorimeter at: Ex 330 nm, Em 420 nm. Quantification of the different OS, including GOS, is performed by calibration of the OS-2AB response with maltotriose external standard and using laminaritriose as internal standard.

Sugars, including lactose, were measured by HPAEC-PAD (i.e. High-Performance Anion- Exchange Chromatography with Pulsed Amperometric Detection) for examples 2-3. Extraction of sugars is carried out in hot water and the sample is injected in the HPAEC-PAD system. Neutral sugars being weak acids are partially ionized at high pH and can be separated by anion- exchange chromatography on a base-stable polymeric column (CarboPac PA20). Sugars are detected by measuring the electrical current generated by their oxidation at the surface of a gold electrode. Post-column addition of NaOH is used to optimize baseline stability, detector sensitivity and linear range.

Example 2: Milk powder prepared with a process according to the first aspect of the invention

An enzymatically-treated milk powder was prepared according to the process of the first aspect of the invention. Fresh milk was mixed with bulking agents, minerals, vitamins to form a slurry with 19% total solids content at a temperature of 50°C. A beta-galactosidase with transgalactosylation activity was contacted with the slurry to convert lactose into GOS. The reaction with the beta-galactosidase was allowed to proceed for a duration of 250 minutes at 50°C. The slurry was heat-treated at 80°C for 100 seconds to inactivate enzymes. Subsequently, a lactase devoid of transgalactosylation activity was contacted with the slurry at 44°C to hydrolyze the residual lactose that has not been converted during the reaction with the beta-galactosidase. The reaction with lactase was allowed to proceed fora duration of 120 minutes. Thereafter, the slurry was heat-treated at 80°C for 30 seconds to inactivate the enzyme and then the slurry was evaporated to reach 45 % total solids. The evaporated slurry was subsequently spray dried to obtain a milk powder. In particular, after spray drying, no residual enzyme activity was detected in the final milk powder.

A reference milk powder without enzymatic hydrolysis was also prepared (cf. table 1- column "Milk powder prepared without enzymatic hydrolysis"). In particular, fresh milk was mixed with bulking agents, minerals, vitamins to form a slurry with 19% total solids content at a temperature of 50°C. The slurry was evaporated to reach 45 % total solids. The evaporated slurry was subsequently spray dried to obtain a milk powder.

Another reference milk powder was prepared by hydrolysis with lactase only (cf. table 1- Milk powder prepared with lactase hydrolysis only"). In particular, fresh milk was mixed with bulking agents, minerals, vitamins to form a slurry with 19% total solids content at a temperature of 30°C. A lactase devoid of transgalactosylation activity was contacted with the slurry at 30°C to hydrolyze the lactose. The reaction with lactase was allowed to proceed for a duration of 4 hours. Thereafter, the slurry was heat-treated at 105°C for 10 seconds by Direct Steam Injection to inactivate the lactase and then the slurry was evaporated to reach 45 % total solids. The evaporated slurry was subsequently spray dried to obtain a milk powder. In particular, after spray drying, no residual enzyme activity was detected in the final milk powder. The formation of GOS and reduction of Lactose is illustrated in Figure 1. The process enables to obtain, in a time-efficient manner (i.e. less than 7 hours), a milk powder with a good nutritional profile. The milk powder of the invention has a substantial amount of fibers, in particular GOS, (cf. table 1) after the process. In addition, the milk powder has a reduced amount of carbohydrates and has a low amount of lactose such that when 25g of the milk powder is reconstituted in 180mL of water, it is considered free from lactose according to Brazilian regulation (cf. table 1).

In particular, it can be observed in Figure 1 that the amount of GOS is decreased during the second enzymatic reaction with the lactase devoid of transgalactosylation activity. This second reaction should be limited in terms of time to avoid losing a too high amount of GOS and therefore losing the benefit of the first enzymatic reactions which produces GOS. With the present process, a very low amount of lactose may be reached within a limited time during the second enzymatic treatment such that the amount of GOS remains substantially high, despite GOS hydrolysis by the lactase. The product has a very low amount of lactose after the second enzymatic reaction. In particular, the product is considered free from lactose, when 25g is reconstituted in 180mL water, according to Brazilian regulation.

Table 1

The obtained milk powder was tasted after reconstitution of 25g milk powder in 180mL water by individuals trained to assess the sensory profile of dairy products. The milk powder exhibited an acceptable organoleptic profile in terms of taste but also of texture. As a conclusion, the process of the first aspect of the invention is efficient and allows to achieve food compositions, e.g. milk powder, with a good nutritional profile, in particular with a substantial amount of fibers and with very low amount of lactose, such that be can be considered free from lactose, when 25g is reconstituted in 180mL water, while maintaining an acceptable organoleptic profile.

Example 3: Milk powder prepared with a process according to the third aspect of the invention

A milk powder was prepared according to the process of the third aspect of the invention. Fresh milk was mixed with bulking agents to form a slurry with 19% total solids content at 40°C. A beta-galactosidase with transgalactosylation activity was contacted with the slurry and allowed to react for the first 250 minutes at 40°C to convert the lactose into GOS. Then, a lactase devoid of transgalactosylation activity was contacted with the slurry to further hydrolyse the remaining lactose. In particular, the beta-galactosidase and the lactase devoid of transgalactosylation activity were allowed to react simultaneously for a duration of 80 minutes at 40°C. The enzymes were inactivated at 80 °C for 115 seconds before proceeding with evaporation to reach 48 % total solids. Thereafter, the evaporated slurry was spray dried to obtain a milk powder.

In particular, after spray drying, no residual enzyme activity was detected in the final milk powder.

The formation of GOS and reduction of lactose is illustrated in Figure 2. The nutritional profile of the milk powder is provided in Table 2.

Table 2

It is observed that a lower amount of GOS is produced and a lower amount of lactose is hydrolysed compared to the process of example 2. However, the amount of GOS remains substantial and satisfactory with this process. Moreover, the amount of lactose reached is low enough to achieve a product free from lactose.

Hence, this highlights that the process of the third aspect of the invention also enables to obtain, in a time-efficient manner (i.e. less than 6 hours), a milk powder with a good nutritional profile. The milk powder has a substantial amount of fibers, in particular GOS, (cf. table 2) after the process. In addition, the milk powder has a reduced amount of carbohydrates and has a low amount of lactose such that it is considered free from lactose, when 25g is reconstituted in 180mL water, according to Brazilian regulation (cf. table 2).

The milk powder was tasted after reconstitution of 25g of the milk powder in 180mL water by individuals trained to assess the sensory profile of dairy products. The milk powder exhibited an acceptable organoleptic profile in terms of taste but also of texture.

As a conclusion, the process of the third aspect of the invention is also efficient and also allows to achieve food compositions, e.g. milk powder, with a good nutritional profile, in particular with a substantial amount of fibers and with very low amount of lactose, such that it is considered free from lactose, when 25g is reconstituted in 180mL water.

Example 4: Milk composition prepared with a process according to the second aspect of the invention at laboratory scale

A milk composition was prepared according to the process of the second aspect of the invention. Skimmed milk powder was mixed at a laboratory scale with water to form a slurry of 20% total solids content at 40°C. Both enzymes, a beta-galactosidase with transgalactosylation activity and lactase devoid of transgalactosylation activity were contacted with the slurry. In particular, the enzymes were allowed to react simultaneously for 30 to 60 minutes to convert the lactose into GOS and to hydrolyse as much as possible lactose. Enzymes were inactivated at laboratory scale by heat-treating the slurry at 90 °C for 10 minutes. The formation of GOS and reduction of Lactose over time is illustrated in Figure 3. In the present example, sugars analysis, including lactose, glucose and/or galactose, was carried out using HPLC method on an amino silica column followed by refractometric detection and quantification by comparison with peak areas of the corresponding peaks obtained for a standard solution.

GOS (wt.%) analysis was carried out using mass balance whereby total sugar (wt.% of lactose + wt.% of glucose + wt.% of galactose) measured by the method above at a given time (Figure 3) was subtracted from the initial total sugar (wt.% of lactose at t=0) measured by the method above to obtain wt.% of GOS.

It has been shown that it is possible to produce substantial amount of GOS while achieving a very low amount of lactose when the two enzymes are allowed to react for at least 30 minutes (figure 3). After tasting, the milk composition exhibits an acceptable organoleptic profile in terms of taste but also of texture.

As a conclusion, it is expected that the process of the second aspect of the invention allows to achieve food compositions, e.g. milk powder, with a good nutritional profile, in particular with a substantial amount of fibers and with low amount of lactose, such that it is considered as low in lactose.

Although the invention has been described by way of example, it should be appreciated that variations and modifications may be made without departing from the scope of the invention as defined in the claims.

Claims

28 CLAIMS

1. A process for preparing an enzymatically-treated food composition comprising the steps of:

(f) allowing the second enzyme to react for 10-180 minutes at 30-55°C to obtain a second enzymatically-treated milk substrate,

(g) fully or partially inactivating the second enzyme in the second enzymatically-treated milk substrate.

2. A process according to claim 1, wherein the first enzyme is allowed to react for 120- 300 minutes at 35-60°C in step (c).

3. A process according to any one of the preceding claims, wherein the second enzyme is allowed to react for 30-150 minutes at 30-50°C in step (f).

4. A process for preparing an enzymatically-treated food composition comprising the steps of:

(c') allowing the first and the second enzyme to react simultaneously for 25-180 minutes at 30-55°C to obtain an enzymatically-treated milk substrate, (d') fully or partially inactivating the first and second enzymes in the enzymatically-treated milk substrate.

5. A process for preparing an enzymatically-treated food composition comprising the steps of:

6. A process according to any one of the preceding claims, wherein the milk substrate of step (a) comprises at least 4 wt.% lactose by dry weight of the milk substrate, preferably 15-60wt%.

7. A process according to any one of the preceding claims, wherein the process further comprises a step of evaporating and/or spray drying the enzymatically-treated food composition.

8. A process according to any one of the preceding claims, wherein the enzymatically- treated food composition comprises at least 1.0 wt.% galactooligosaccharides, preferably at least 4 wt.%, more preferably at least 8wt.% galactooligosaccharides.

9. A process according to claim 8, wherein the enzymatically-treated food composition comprises 1.0wt%-35wt% galactooligosaccharides, preferably 8wt%-15wt% galactooligosaccharides.

10. An enzymatically-treated food composition comprising:

-10-40 % by dry weight of milk protein; and

-10-55% by dry weight of a mixture of lactose, glucose, galactose and galactooligosaccharide, said mixture containing: 0-4 % by weight of lactose, 8-45% by weight of glucose, 0.1-25% by weight of galactose and 35-90% by weight of galactooligosaccharide.

11. An enzymatically-treated food composition according to claim 10, which is obtainable by a process according to any one of claims 1 to 9.

12. A food product comprising an enzymatically-treated food composition according to claim 10 or 11.

13. A process for preparing a food product which comprises: the steps of preparing an enzymatically-treated food composition according to any one of claims 1-9, or, the step of providing an enzymatically-treated food composition according to claim 10 or 11.

14. A process for preparing a food product according to claim 13 or a food product according to claim 12, wherein the food product is selected from the list consisting of dairy products, confectionery products, beverage whiteners, beverage creamers, powdered cocoa beverages, powdered malt beverages, powdered or liquid coffee mix products, and/or nutritional or health-related food products.